1 mod mock_writer {
2 use futures::io::AsyncWrite;
3 use std::io;
4 use std::pin::Pin;
5 use std::task::{Context, Poll};
6
7 pub struct MockWriter {
8 fun: Box<dyn FnMut(&[u8]) -> Poll<io::Result<usize>>>,
9 }
10
11 impl MockWriter {
new(fun: impl FnMut(&[u8]) -> Poll<io::Result<usize>> + 'static) -> Self12 pub fn new(fun: impl FnMut(&[u8]) -> Poll<io::Result<usize>> + 'static) -> Self {
13 Self { fun: Box::new(fun) }
14 }
15 }
16
17 impl AsyncWrite for MockWriter {
poll_write( self: Pin<&mut Self>, _cx: &mut Context<'_>, buf: &[u8], ) -> Poll<io::Result<usize>>18 fn poll_write(
19 self: Pin<&mut Self>,
20 _cx: &mut Context<'_>,
21 buf: &[u8],
22 ) -> Poll<io::Result<usize>> {
23 (self.get_mut().fun)(buf)
24 }
25
poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>>26 fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
27 panic!()
28 }
29
poll_close(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>>30 fn poll_close(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
31 panic!()
32 }
33 }
34 }
35
36 /// Verifies that the default implementation of `poll_write_vectored`
37 /// calls `poll_write` with an empty slice if no buffers are provided.
38 #[test]
write_vectored_no_buffers()39 fn write_vectored_no_buffers() {
40 use futures::io::AsyncWrite;
41 use futures_test::task::panic_context;
42 use std::io;
43 use std::pin::Pin;
44 use std::task::Poll;
45
46 use mock_writer::MockWriter;
47
48 let mut writer = MockWriter::new(|buf| {
49 assert_eq!(buf, b"");
50 Err(io::ErrorKind::BrokenPipe.into()).into()
51 });
52 let cx = &mut panic_context();
53 let bufs = &mut [];
54
55 let res = Pin::new(&mut writer).poll_write_vectored(cx, bufs);
56 let res = res.map_err(|e| e.kind());
57 assert_eq!(res, Poll::Ready(Err(io::ErrorKind::BrokenPipe)))
58 }
59
60 /// Verifies that the default implementation of `poll_write_vectored`
61 /// calls `poll_write` with the first non-empty buffer.
62 #[test]
write_vectored_first_non_empty()63 fn write_vectored_first_non_empty() {
64 use futures::io::AsyncWrite;
65 use futures_test::task::panic_context;
66 use std::io;
67 use std::pin::Pin;
68 use std::task::Poll;
69
70 use mock_writer::MockWriter;
71
72 let mut writer = MockWriter::new(|buf| {
73 assert_eq!(buf, b"four");
74 Poll::Ready(Ok(4))
75 });
76 let cx = &mut panic_context();
77 let bufs = &mut [
78 io::IoSlice::new(&[]),
79 io::IoSlice::new(&[]),
80 io::IoSlice::new(b"four")
81 ];
82
83 let res = Pin::new(&mut writer).poll_write_vectored(cx, bufs);
84 let res = res.map_err(|e| e.kind());
85 assert_eq!(res, Poll::Ready(Ok(4)));
86 }
87